Greg Dyke is wrong. His description of the BBC and BSkyB as the two 800lb gorillas in British broadcasting may help to make the case for beefing up ITV into a third gorilla, but it doesn't do justice to the relative positions of the two big beasts. In the battle for jungle supremacy with BSkyB, the BBC doesn't have a chance.

Just think where the two corporations stand. BSkyB has emerged from the frenzy of negotiations over the Communications Act virtually unscathed. Yes, any ambitions (hotly denied, of course) to grab a slice of terrestrial TV through Five, the rebranded Channel 5, may face a few more hurdles than Downing Street first planned, but in retrospect maybe the whole ownership farrago was a clever red herring.

As the Lords debate on Five reached its peak in July, I was told separately by two very well informed observers that the real ownership threat to BSkyB had long since gone: the threat was that the Government might force it to separate the wholesale business of operating a satellite platform for other channels from the retail business of selling channels such as Sky Sports direct to consumers.

This could have been a serious problem. It was recommended in submissions to Government by both the BBC and Channel 4, and would at some point have been considered by officials within the Department of Culture, Media and Sport. A forced separation would have made major inroads into Sky's dominance of satellite television - and, of course, its profits. By comparison, a couple of extra obstacles to owning Five are very small beer.

Having played a blinder on ownership, Sky can now add exclusive rights to the Premiership until 2007. There will be posturing from the European Commission about anti-competitive behaviour, but you can't argue with the absence of serious rival bids.

Then, of course, there are Sky's programming obligations. There aren't any. Sky's entertainment package consists essentially of imported programmes mixed with original commissions based on the sex theme.

BSkyB's chief executive, Tony Ball, talked in his McTaggart lecture last week of Sky's range of programmes providing viewers with 'quality along with variety' but he knows, as does Rupert Murdoch, that this package would be virtually worthless without exclusive sport and movies. The figures speak for themselves: more than £1.1 billion spent on sport and movies in 2002/03 compared to £133 million on entertainment and news.

None of this should detract, as Ball rightly pointed out, from the huge financial gamble which produced this particular gorilla. It is about to pass its own 7 million subscriber target several months early and is predicting 8 million by the end of 2005. This year saw the first pre-tax profits - £260m - since the launch of digital satellite in 1998. BSkyB is beginning to reap the benefit of its quasi-monopoly in satellite TV.

By contrast, there is the BBC. As the recipient of public money, it has to be accountable - but the number of constraints, reviews, conditions and assessments being imposed on it is reaching epidemic proportions. This is a gorilla bound hand and foot by public scrutiny.

Last week saw the latest review, this time a 'comprehensive and thorough' examination of the BBC's online services by former Trinity Mirror chief executive Philip Graf. He will look at quality, value for money, how the services fit the BBC's public service remit and their impact on competition.

Next comes the first of Ofcom's triennial reviews of public service broadcasting, which will be the new regulator's first opportunity to pass independent judgment on the whole of the BBC. Almost simultaneously there will be a government review of the BBC's digital services - not just BBC 3 and 4 but both its children's channels and all of the digital radio stations.

Over the next 18 months there will barely be a BBC programme that will not be held under a microscope by someone outside the BBC charged with holding every corporate decision to account. And that's without the forensic analysis of BBC journalism by the Hutton inquiry. This unprecedented level of public scrutiny can only have one result: to produce recommendations that will limit the BBC's room for manoeuvre.

The irony is that a central part of the Government's own strategy was to maintain a vigorous BBC to promote all the cultural and democratic advantages of public service broadcasting. Culture Minister Tessa Jowell was effusive about this in her Edinburgh speech, but she doesn't seem to appreciate the distorting impact of BSkyB's muscle, which she herself set loose.

In the end, there is only one gorilla. Its growth in size and profitability is all but unstoppable, assisted as ever by assiduous promotion in the Murdoch press. And within 10 years, this particular gorilla will have made monkeys of all its competitors.

· Steven Barnett is professor of communications at the University of Westminster